高寒沼泽湿地土壤湿度对放牧强度的响应

在青藏高原隆宝滩高寒沼泽湿地进行不同放牧强度试验，应用统计学成对数据的t检验方法，定性研究围栏封育（EN）、轻度放牧（LG）、中度放牧（MG）、重度放牧（HG）、自由放牧（GU）5种放牧处理对不同深度土壤湿度的影响差异。结果表明：随着牧压强度的增加，影响湿地土壤水分含量的显著性也增强。EN和LG、MG处理对土壤水分含量的影响各个层次都不显著；HG对LG和MG的差异随深度的增加而减弱； GU和HG处理的影响最为显著，从土壤表层到50 cm深度，均表现为LG>GU、MG>GU、HG>GU、EN>GU和EN>HG、LG>HG。自由放牧和重度放牧加大土壤水分的蒸散，导致湿地土壤水分含量降低，加速湿地退化。合理有序的放牧活动是减少湿地土壤水分蒸发，减缓湿地退化的有效手段。

Astudy on response of soil moisture of alpine wetland to grazing intensity

The impact of different grazing intensity,including enclosure(EN),light grazing(LG),moderate grazing(MG),heavy grazing(HG),free grazing(FG),on soil moisture was studied by using paired T test method in Longbao on Tibetan Plateau.The results showed that the significant level of impact on soil was increased with the increasing of grazing intensity.The difference of soil moisture between EN and LG,EN and MG were not significant in all soil layers;with increasing of depth,differences between HG and LG,HG and MG were decreased;the impacts of FG and HG treatments were the most significant.The order of treatment impact from soil surface to 50 cm was LG>GU,MG>GU,HG>FG,EN>FG and EN>HG,LG>HG.The FG and HG enhanced evapotranspiration,reduced soil moisture,and accelerated the wetland degeneration.Proper grazing management was critical to reduce evapotranspiration and degeneration.